[M68k][MIR](2/8) Changes in the target-independent MIR part

 - Add new callback in `TargetInstrInfo` --
  `isPCRelRegisterOperandLegal` -- to query whether pc-rel
   register MachineOperand is legal.
 - Add new function to search DebugLoc in a reverse ordering

Authors: myhsu, m4yers, glaubitz

Differential Revision: https://reviews.llvm.org/D88386

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index 8ed1701..f31eae9 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -1401,6 +1401,14 @@ MachineBasicBlock::findDebugLoc(instr_iterator MBBI) {
   return {};
 }
 
+DebugLoc MachineBasicBlock::rfindDebugLoc(reverse_instr_iterator MBBI) {
+  // Skip debug declarations, we don't want a DebugLoc from them.
+  MBBI = skipDebugInstructionsBackward(MBBI, instr_rbegin());
+  if (!MBBI->isDebugInstr())
+    return MBBI->getDebugLoc();
+  return {};
+}
+
 /// Find the previous valid DebugLoc preceding MBBI, skipping and DBG_VALUE
 /// instructions.  Return UnknownLoc if there is none.
 DebugLoc MachineBasicBlock::findPrevDebugLoc(instr_iterator MBBI) {
@@ -1411,6 +1419,16 @@ DebugLoc MachineBasicBlock::findPrevDebugLoc(instr_iterator MBBI) {
   return {};
 }
 
+DebugLoc MachineBasicBlock::rfindPrevDebugLoc(reverse_instr_iterator MBBI) {
+  if (MBBI == instr_rend())
+    return {};
+  // Skip debug declarations, we don't want a DebugLoc from them.
+  MBBI = next_nodbg(MBBI, instr_rend());
+  if (MBBI != instr_rend())
+    return MBBI->getDebugLoc();
+  return {};
+}
+
 /// Find and return the merged DebugLoc of the branch instructions of the block.
 /// Return UnknownLoc if there is none.
 DebugLoc